Inventive concepts relate to semiconductor devices, and more particularly, to semiconductor devices having an on-die termination (ODT) structure that reduces current consumption, and termination methods performed in the semiconductor devices.
Semiconductor devices include an input circuit for receiving signals from an external circuit via an input pad, and an output circuit for providing internal signals to the external circuit. As the operational speeds of digital products increase, swing widths of signals interfaced between semiconductor devices decrease. A reason for the decrease of the swing widths is to minimize the time taken to transmit the signals. However, as the swing widths decrease, the semiconductor devices are affected by external noise, and a reflection signal generated by impedance mismatch affects an interface between semiconductor devices. When impedance mismatch occurs, high-speed data transmission is difficult to achieve, and data output from an output terminal of a semiconductor device may be distorted. In this case, a semiconductor device on a reception side may receive a distorted output signal and cause problems such as setup/hold failure and miss-judgment. To address these problems, semiconductor devices required to operate fast include an impedance matching circuit installed near a pad within an integrated circuit chip.